Fix TermLogger and ProgressLogging compatibility

[brendanjohnharris]

Previously, the TermLogger progress bar printed nothing because the minimum log level was set to Info rather than ProgressLevel, and the update! method would increment by the value of i (rather than setting the value to i, as suggested by the docs and code base), causing the progress bar to overflow

To test the TermLogger functionality, I also made sure a custom io could be passed to TermLogger (and therefore ProgressBar)

ProgressLogging integration should now work as described in the docs